(navigation image)
Home American Libraries | Canadian Libraries | Universal Library | Community Texts | Project Gutenberg | Children's Library | Biodiversity Heritage Library | Additional Collections
Search: Advanced Search
Anonymous User (login or join us)
Upload
See other formats

Full text of "Chemical changes in stored grains : a selected and annotated bibliography"

Historic, archived document 

Do not assume content reflects current 
scientific knowledge, policies, or practices. 



& 



A"^Ac.s 

no. I'M 



ACE-191 

Go -p. I NM-227 



T' 



UNITED STATES DEPARTMENT OF AGRICULTURE 

Agricultural Research Administration 

Bureau of Agricultural Chemistry and Engineering 






U. S. Depa 



— __ 



CHEMICAL CHANGES IN STORED GRAINS 
A Selected and Annotated Bibliography 



Prepared by 
Carol M. Jaeger, Assistant Statistician 
Commodity Development Division 
Northern Regional Research Laboratory 



Peoria , Illinois 
March 1943 



FOREWORD 

The Ever Normal Granary program presupposes the accumulation of larger- 
than-normal quantities of grain and its storage for longer-than-usual 
periods of time . This program was adopted by the U . S . Department of 
Agriculture in 1938, and recently was subscribed to by the three other 
major wheat-exporting countries and by Great Britain under the terms of 
the World Wheat Agreement of June 27 , 194-2. 

The possibility for grain to accumulate under an Ever Normal Granary 
program is evidenced by the size of crop carry-overs in the United States 
in recent years in comparison with those of former years. In the case 
of wheat the July 1 carry-over increased from an average of 238 million 
bushels during the 10-year period, 1929-38, to 282 million bushels in 

1940, 385 million bushels in 1941, 632 million bushels in 1942, and to 
an estimated July 1, 1943 carry-over of 700 million bushels. A similar 
tendency is shown for corn. From an average of 212 million bushels for 
the 10-year period 1929-38 the October 1 carry-over rose to 583 million 
bushels in 1939, 695 million bushels in 1940, 646 million bushels in 

1941, and 492 million bushels in 1942. 

Evidence that under the Ever Normal Granary program some grain is now 
stored longer than one crop season, the former usual limit, may be had 
from the Commodity Credit Corporation report of July 1942. This report 
shows that the Corporation had in storage approximately 200 million 
bushels of 1941 crop wheat and 100 million bushels of 1940 or some 
previous crop wheat. Until recently, a similar situation existed with 
regard to corn. 

Because of the existence of these large accumulations and because of the 
war situation necessitating the maintenance of adequate stocks of 
grain to meet full domestic, lend-lease, and post-war foreign relief re- 
quirements, the possible effect of length of storage on the physical and 
chemical properties of grain becomes an important question. A full 
knowledge of the character and extent of these changes is necessary for 
the proper utilization of such grain. 

The Official U. S. Grain Standards have been developed to cover adequate- 
ly the changes in the physical aspects of the grain resulting from 
storage. But up to the present time not much attention has been given 
to chemical changes not reflected in the physical appearance of the 
kernels. These chemical changes, however, may be of utmost importance in 
the use of the grain both on the farm and in industry. To make available 
the sources of information pertaining to this particular aspect of 
storage, the following selected and annotated bibliography has been pre- 
pared. 

The sources consulted in preparing this bibliography were limited to 
those available at the Northern Regional Research Laboratory. 



SUMMARY 

The literature concerning the effect of storage on the chemical composi- 
tion of grain is marked by the dearth of specific results. Up to very 
recent years the greatest amount of work seems to have been reported on 
the products of grain, principally flour , rather than on the grain it- 
self. 

On the basis of available information it appears that temperature and 
moisture are the fundamental factors concerned with the deterioration 
of stored grain and the products therefrom. Type of container or type 
of storage, insect infestation, stage of maturity of the grain and its 
condition when stored are contributing or secondary factors. 

It appears that, in general, wheat with 13 percent or less moisture will 
not be damaged by heating in storage, while wheat with more moisture is 
likely to be damaged. (See item No. 52). The line between safe and un- 
safe storage is not a sharp one and wplll vary with temperature, humidity 
of the air, and other factors. In this connection it has been found 
that wheat with high moisture content may be stored at 41° F., or lower 
temperatures, for many months without suffering damage to its milling 
and baking qualities. (See item No. 82). However, under normal tempera- 
ture conditions it appears that the baking quality of wheat suffers on 
prolonged storage; in some cases showing very marked deterioration. 

In the case of all grains or beans it has been found that viability is 
maintained for long periods when the commodity is stored with low mois- 
ture content at either low or relatively high temperatures. 

The available information on the actual chemical changes in stored grain 
is not sufficient to support general 'conclusions. Specific experiments 
have indicated that the vitamin A content of stored corn decreases by as 
much as 50 percent after 3 or 4- years. (See item No. S3). Another 
series of experiments showed notable decreases in the percentage of 
sugar in stored corn, while for barley and oats small decreases in sugar 
content were shown, and for wheat a slight increase was noted. (See 
item No. 42) . 

Experiments on the chemical changes in stored flour indicate that gluten 
quality is affected by the presence of unsaturated fatty acids which 
have a tendency to increase when the flour is stored under unfavorable 
conditions. (See item Nos. 4, 35, 37, 43, 70, 73). The observed altera- 
tions occurring in the proteins from storage of wheat, corn, soybeans and 
flour are a decrease in solubility, a partial breakdown of the proteins 
as indicated by the amount of nitrogen precipitable by trichloracetic 
acid and by an increase in amino nitrogen, and decrease in digestibility. 
(See item Nos. 31, 32, 33, 34). 

The changes occurring in the carbohydrate and oil constituents as the 
result of storage have been discussed only with coincident changes in 
gluten. 



CHEMICAL CHANGES IN STORED GRAINS 
A Selected and Annotated Bibliography 

1. Aamodt, 0. S. , and McCalla, A. G. Quality and keeping properties 
of flour from wheat grown on the black and gray soils of Alberta. 
Can. Jour. Research. Sec. C. Vol. 13. September 193$. 

'Weight per bushel and milling yields of hard red spring wheats 
grown on the black soil at Edmonton were the same as for the same 
varieties grown on the gray soil at Fallis. Grade, protein content, 
and baking quality of Edmonton grown samples were superior. The 
flour from most of the Edmonton grown samples retained its quality 
for at least two years after milling, but flour from most of the 
Fallis grown samples had deteriorated so much during 10 months' 
storage that it was unfit for breadmaking. Flour from Reward showed 
less deterioration than that from any other standard variety grown 
at Fallis. It also had the best original baking quality, and is 
the only one of the recommended varieties considered satisfactory 
for the gray soil area." 

2. Anderson, J. Ansel. Effect of insecticides on wheat quality. 
pp. 29-30, Fifteenth Annual Report, Board of Grain Commissioners, 
Grain Research Laboratory, Winnipeg, Manitoba. 1942. 

"Larvacide, Larvacide mixed with carbon-tetrachloride, Weevil- 
cide, Weevil-Insecticide and We s to fume all taint wheat, but the 
taints produced do not persist on subsequent aeration. It is be- 
lieved that the amount of aeration produced by the normal handling 
of fumigated grain will be sufficient to reduce any taint to a 
level which is barely perceptible, even if twice the normal dosage 
of any of the fumigants is applied. Five times the normal dosage 
does not have any apparent injurious effect on either wheat 
strength or baking quality." 

3. Back, E. A., Cotton, R. T., and Ellington, G. W. Ethylene oxide as 
a fumigant for food and other commodities. Jour. Econ. Entomology. 
Vol. 23, No. 1, pp. 226-231. February 1930. 

"In ethylene oxide, when used as directed, we have a fumigant 
which, in addition to possessing freedom from the fire and explo- 
sion hazard and extreme toxicity to man, does not appear to leave 
in or upon the treated materials obnoxious odors, or residues harm- 
ful to man or animals. It is believed that many commodities will 
be fumigated more successfully and with less danger when the de- 
tails of application, particularly with carbon dioxide, have been 
worked out." 



4. Barton-Wright, E. C. Studies on the storage of wheaten flour: III. 
Changes in the flora and the fats and the influence of these changes 
on gluten character. Cer. Chem. Vol. 15, No. 4, pp. 521-54-1. 

July 1938. 

"An investigation has been made of the changes that take place 
in the bacterial and fungal flora of flour kept under storage condi- 
tions. It was found that the bacterial numbers always diminish with 
increasing time... 

"Deterioration of gluten quality during storage of flour, es- 
pecially low-grade flours, was found to depend on the unsaturated 
fatty acids present in the oil fraction. In flours with a moisture 
content of 16 percent and over, the oil content fell rapidly during 
storage and this was found to coincide with increase in fungal 
numbers and was not accompanied by deterioration in gluten quality. 

"In low-grade flours of normal moisture content (14- to 15 per- 
cent) or less with a high oil content it was found that after 6 to 
8 weeks' storage the gluten tended to break up on washing, whereas 
in the moist samples the gluten improved in quality. This improve- 
ment in the quality of the gluten was found to be due to (1) the 
removal of fats and fatty acids by fungi and (2) some improving ac- 
tion due to the fungi themselves. 

"The effect of different saturated and unsaturated fatty acids 
on gluten is described and discussed. Saturated acids of high 
molecular weight produce only slight shortening effect in gluten. 
Unsaturated acids produce serious damage in gluten. This damage is 
due to the presence of double bonds in the acid since when these are 
removed, e.g., by bromination, the damaging effects are removed. 

"Free carboxyl groups are also an essential factor in gluten 
damage since this is not caused by esters (e.g. fats themselves) or 
by salts of unsaturated fatty acids. 

"Gluten damage by unsaturated acids is not due to pH changes as 
the effect of, e.g., oleic acid on dough pH is very small (0.1)." 

5. Beslcy, H. J., and Baston, G, H. Acidity as a factor in determining 
the degree of soundness in corn. U. S. Dcpt. Agr. Bui. No. 102, 1914. 

"The degree of acidity of corn should not necessarily be con- 
sidered a measure of the percentage of individual kernels that are 
visibly damaged. It is the soundness and quality of the corn which 
is indicated by the acidity test, and the results of this investiga- 
tion suggest the acidity test as a method to be used in determining 
accurately the soundness and quality of corn." 

A number of tables are presented indicating relationships between 
acidity and germination, temperature, destination of corn, etc. 



6. Bracken, A. F., and Bailey, C. H. Effect of delayed harvesting 
on quality of wheat. Cer. Chen. Vol. 5, No. 2, pp. 128-14-5. 
March 1928. 

"The baking studies gave proof that wheat which had remained 
unharvested in the field for 50 days after ripe, subjected to 
alternate wetting and drying, showed no indication of deteriora- 
tion as determined by loaf volume and loaf texture. 

"Thus it may be stated as a result of these tests that dark 
hard wheat of the Turkey Red type does not deteriorate in quality 
upon standing uncut in the field when' subjected to alternate 
wetting and drying, in spite of the fact that the grains bleach 
and lose weight per measured volume." 

7. Briggs, Charles H. What do baking tests disclose? Northwestern 
Miller. Vol. 6, No. 8, p. 745. August 28, 1929. 

"The amount of gluten which the flour contains is often 
correlated more nearly with the water absorption than is the mois- 
ture content. Again, the water absorption is often inversely 
proportional to the amount of soluble carbohydrates (sugars, etc.) 
present, which may be taken as a crude measure of the amount of 
enzymic action which has taken place, and particularly, though in- 
directly, of the proteolytic action that has occurred before the 
dough is made and that will occur during fermentation." 

8. Cathcart, William H., and Killen, Edward J. Changes in flour on 
storage with special reference to the effect of different types of 
bags. Cer. Chem. Vol. 16, No. 6, pp. 798-817. 1939. 

"Two different samples of chemically bleached and matured 
flour were stored separately in four different "types of bags, name- 
ly ordinary cotton, paper-lined, jute, and grain. They were stored 
under average commercial bake-shop conditions. The samples were 
analyzed at regular intervals for moisture, ash, protein, and ab- 
sorption, and baking tests were made. The kind of bag had little 
effect on the analyses of the baking quality of the flour. In all 
cases absorption increased during storage, ash and protein showed 
no change, and the baking quality in one sample fell off after the 
fourth month and in the other after the sixth month. Deteriora- 
tion in the latter case was due to infestation." 

9. Coleman, D. A. Unsoundness in wheat. Grain Inspectors' Letter. 
June 13, 1931. 

"The spoilage of wheat is the direct result of harvesting and 
storing of wheat with an excess of moisture. It makes but little 
difference whether the wheat is cut and stacked in a wet condition, 
or whether the wheat is threshed and stored with excess moisture, 



the ultimate results are the same. Stimulated by the high moisture 
content in the grain, rapid respiration or fermentation takes place, 
heat develops, with the result that the grain spoils, the extent of 
the spoilage depending upon hew long the wheat has been exposed to 
the fermentation process and how much heat of fermentation has 
developed." 

10. Coleman, D. A., and ^othgeb, B. E. Heat-damaged wheat. U. S. Dept. 
Agr. Tech. Bui. No. 6. 1927. 

Tables showing the chemical composition of heat-damaged wheat 
are given along with data on baking results. 

11. Coleman, D. A., Rothgeb, 3. E., and Fellows, H. 0. Respiration of 
sorghum grains. U. S. Dcpt. Agr. Tech. Bui. No. 100. 1928. 

"Storage tests made under laboratory conditions bear out in a 
general way the findings of the respiration studies; namely that if 
the temperature is sufficiently high (100° F. or more) sorghum grains 
that contain over 14- percent of moisture will go out of condition." 

12. Cox, J. Hi The drying for milling purposes of damp and garlicky 
wheat. U. S. Dept. Agr. Bui. No. 455. 1916. 

"The results of these investigations show practically no bad 
effects from the drying of wheat at 140° F. and indicate that this 
temperature is probably the most satisfactory for the drying of wheat, 
either with or without garlic, for milling purposes." 

13. Culbertson, C. C. Debunk fear of old corn. Wallaces' Farmer and 
Iowa Homestead. Vol. 67, No. 14, p. 11. July 11, 1942. 

C. C. Culbertson, of the Iowa Agricultural Experiment Station, 
stated that throughout Iowa during the year there had been cases of 
edema etc., apparently caused by feeding vitamin-poor old corn, but 
that in most of the edema cases the steers had been getting both old 
hay and old corn. If good legume hay is fed along with old com. 
there should be no such trouble. In this year's experiment results 
showed that there was less difference than was at first indicated in 
the feeding of old com compared to new, both with the corn fed 
shelled and in combination with alfalfa hay. As a matter of fact, it 
was found that some 1937 corn did a little better than the 194-0 corn 
because the latter — although three years younger — had dried to a 
harder condition. 

14. Duvel, J. W. T. The deterioration of corn in storage. U. £. Dept. 
Agr. Cir. No. 43. 1909. 



15. Fenton, F. C, and Swanson, C. 0. Studies on the qualities of com- 
bined wheats as affected by type of bin, moisture and temperature 
conditions. Cer. Chem. Vol. 7, pp. 428-448. 1930. 

p. 439 - Table shows germination, and composition as affected by 
different conditions of storage — (no general conclusions). 

16. Fifield, C. C, and Bailey, C. H. The march of acidity in stored 
flours. Cer. Chem. Vol. 6, No. 6, pp. 530-40. November 1929. 

"It has been generally observed that the acidity of flour 

increases progressively with the lapse of time The rate of 

change in acidity has appeared to be a function of flour grade, 
moisture content, humidity of the atmosphere, temperature, and 
possibly other factors." 

17. Fisher, E. A., Halton, P., and Carter, R. H. Studies on the 
storage of wheaten flour: I. The influence of storage on the 
chemical composition and baking quality of flour. Ccr. Chem. 
Vol. 14, No." 2, pp. 135-161. March 1937. 

"It is well known that wheat flours improve in baking quality 
during storage. This improvement continues for some time until 
it reaches a maximum, after which progressive deterioration sets 
in, the flour becoming eventually unfit for breadmaking. Flours, 
even when made from good sound wheat, vary widely in their 
response to storage After the first deterioration has pro- 
ceeded for some time a second improvement sets in, which in turn 
may be followed by a second deterioration. A similar periodicity 
occurs in changes observable in many of the chemical properties, 
among which may be mentioned hydrogen-ion concentration, buffer 
value, total acidity, soluble nitrogen and, above all, in amount 
and quality of the washed out gluten. These changes are much more 
marked and take place more rapidly the higher the moisture contents 
of the flours, and also show very marked differences according to 
the nature and grade of the flour Flour which has become use- 
less for breadmaking by prolonged storage, or by less prolonged 
storage under unsatisf actor;/ conditions, has a marked improving 
action when added at the rate of 2 percent to otherwise untreated 
flour. The improvements resulting are improved dough body and 
stability, improved oven spring, and improved colour, softness and 
spring of crumb, and are quite comparable with those brought about 
by heat treatment processes, or by the use of over-heat-treated 
flours. " 

18. Franke, Erich — head of the production laboratory of the Fleischmann 
Yeast Company at Pekin, Illinois. Observations, based on 15 years' 
experience in fermentation industries in Czechoslovakia and this 
country, on characteristics of stored grains. 

Rye and corn begin to show a resistance to malt saccharifica- 
tion some 8 or 9 months after harvesting. This resistance remains 



essentially the same from then on. Treatment with malt diastase 
for a longer time will increase the sac char if ication to the origi- 
nal value. Addition of more enzyme will help to a certain extent , 
but will not bring saccharif ication to the original rate. These 
observations have been repeated year after year and it is evident 
that they are not due to seasonable variations. Experiments have 
shown that neither the moisture nor the nitrogen content of the 
grains changes. Change in strength of the malt diastase was investi- 
gated but showed no difference, indicating the difference to be in 
the grain itself. 

- It was further noted that during saccharif ication, starch from 
fresh grain stained first blue, then violet, then red, and finally 
was colorless with iodine, while the old grain went from blue to 
colorless without going through the other colors. 

In connection with the storage of potatoes for use by dis- 
tilleries in the production of alcohol, it was found that the piping 
of carbon dioxide from the distillery to the storage bins prolonged 
the satisfactory storage period of the potatoes. This obviously 
slows down respiration and delays enzymic changes . 

19. Geddes, W. F. Discussion before a meeting of the Minneapolis chapter, 
Society of Grain Elevator Supt's. - Minneapolis, October 27, 194-2. 
Feedstuffs, Vol. 14, No. 45, p. 14. November 7, 1942. 

"Regardless of the effects of various mold growths on grain 

heating, the grain respiration process is a common cause of damage. 
By studies of the carbon dioxide produced, curves have been drawn to 
indicate safe moisture limits for various types of grain in storage 
when other things are equal. The .'break' in the curve, that is, the 
danger point, is reached more rapidly for some grains than others, 
the oil content being a major factor in this. Flax, for example, has 
the earliest break, rye the latest. Corn curves indicated that at 
11 percent moisture virtually no carbon dioxide (cr respiratory heat) 
was produced. At 12 percent a small amount is evolved, and at 
14 percent a much larger amount was obtained over a given period. 
The break occurs there — above 14- percent heating mounts rapidly. 
Cereal grains were fairly well grouped, corn being slightly quicker 
to heat than others. The tests were conducted at a relatively high 
initial temperature . " 

Dr. Geddes explained that since oil was not miscible, the mois- 
ture content of non-oil portions of grains was higher than would be 
indicated by grain weight, thus accounting for the more rapid heat- 
ing of grains higher in oil. 

ITork on soybeans was begun only last year. Because of its oil 
content, its heating curve falls between corn and flaxseed. 



20. Grain and Feed Journals. Yi/heat treated with ethylene keeps better. 
Grain and Feed Jour., Vol. 88, No. 6, p. 267. March 25, 1942. 

"Ein-burning of vfheat having a high moisture content can be re- 
tarded by the use of ethylene gas in the storage bins, research 
workers of the U. S. Department of Agriculture and the Department of 
Milling Industry at Kansas State College have found. The gas, at a 
concentration of approximately one part in 10 thousand of air in 
the bin was blown into the bin while the damp wheat was being 
stored.". . . . 

The treatment will reduce the rate of heating and will permit 
the farmer or grain handler to store high-moisture wheat for 
approximately two weeks, until it can be dried down to a safe mois- 
ture content. 

"YVheat that was allowed to mature fully in the field before 
harvesting was also included in the ethylene storage research 
project. The investigators found that the gas apparently 
hastened the ageing process through which wheat must go after 
harvesting before it will make flour of satisfactory baking 
quality." 

21. Grain and Feed Journals. Sick wheat. Vol. 89, No. 1, p. 11. 
July 8, 1942. 

"Sick wheat is but a new name for an old condition result- 
ing from storage when damp. Prior to the advent of the combine 
when wheat was cut with the binder and stored in barns or stacks 
before threshing, sick wheat was usually referred to as mov/- 
burned, stack-burned, header damaged. Each condition was usually 
accompanied by a musty or sour odor and such wheat was considered 
unfit for milling purposes. Briefly stated, the combine plus wet 
grain, plus storage,- leads to heating, mustiness and enzymic 
action — result sick wheat." 

22. Grain & Feed Journals. Watch out for sick wheat. Grain & Feed 
Jour. Vol. 89, No. 3, p. 109. August 12, 1942. 

"High moisture, and failure to turn wheat sufficiently during 
the early weeks of storage are the immediate causes of sick wheat. 
0. F. Phillips, Chairman of the Board of Review at Chicago, top 
grain supervision office of the U. S. De.pt. Agr. says: 'Sick wheat 
is suffocated wheat.. The germ of the wheat berry is a living 
organism. It breathes. When suffocated for lack of air, inter- 
molecular respiration takes place. This breaks down the starch 
cells and the wheat starts to deteriorate. The germ turns color. 
It becomes gray, or reddish brown, or black. The bran coat is 
soon affected and the berry takes on a dead, lifeless, sometimes 
skin burned appearance. If sick wheat is left to natural 
processes it becomes heat damaged. Eventually the whole berry 



8 



will become black and charred.'" 

"Sick wheat is not a new condition that has suddenly dropped 
upon us. It is merely another term for an old condition. Other 
terms used for the same thing in farm parlance are 'bin-burned' , 
'mow-burned', 'header damaged 1 , and 'stack-burned'. Truth is 
that wheat so damaged was left to look after itself when it was 
too wet to do so. The result is sick wheat. That was now the 
federal department of agriculture officials looked at it back in 
1925 when the term 'sick' originated." 

23. Grain Inspectors' Letter. Issued from General Field Headquarters, 
Grain Division, Bureau of Agricultural Economics. October 1938. 

"During harvest- time there was considerable rainfall in a part 
of the winter wheat belt. It appears, as a result of this condi- 
tion, that quite a volume of wheat with relatively high moisture 
content went into farm storage. As a result, there has been more or 
less development of storage damage or 'sick wheat', some of which is 
now arriving at the various terminal markets . " 

24.. Greaves, J. E. Changes in flour during storage. Farm and Home 
Science, Vol. 3, No. 2, Utah Agr. Exp. Sta. June 1942. 

"In this experiment 13 fifty -pound sacks of flour were 

stored for three years." 



"The water-soluble phosphorus content of the flour in- 



creased and the alcohol soluble phosphorus content decreased as the 
flour aged. Therefore, it is evident that during storage there was 
a slow breaking down of the complex phosphorus -carrying proteins and 
of the fat-carrying phosphorus. Inasmuch as yeast requires large 
quantities of phosphorus in its metabolism, it is probable that this 
is one of the benefits resulting from the ageing of flour. 

"During the early period of storage autolytic changes resulting 
in protein cleavage may have been rapid enough to neutralize not 
only the acid produced but to have combined with some at first 
present. Later protein cleavage may have decreased relative to acid 
production with the resulting measurable increase in acidity, or 
what is more probable, the acids in the flour were used up in the 
normal metabolism of the cell enzymes. This latter supposition im- 
plies that the decrease in acidity is owing to the enzymic action 
which plays a part in the normal ripening of the wheat. Therefore, 
what we have is the normal ripening process, and it does not seem 
unreasonable to assume that this enzymic process may occur during the 
storage period of flour. Possibly the ripening process is complete 
at the point of neutrality and the increase in acidity comes from 
decomposition. This may closely correlate with other beneficial 
changes occurring in flour, and if sufficiently studied may give an 



exact criterion for measuring changes in storages of not only grains 
and grain products but also fruits and vegetables. 

"In most of the flours the water-soluble carbohydrates increased 
owing to storage. Some flours remained unchanged and a few decreased 
in water-soluble carbohydrates. Two facts stand out from a study of 
the changes in the carbohydrates as the result of storage: (1) 
There was a variation in water-soluble reducing sugars occurring in 
different flours, and (2) there was a tendency for the water-soluble 
carbohydrates to increase during storage, thus indicating a diastatic 
action. This increase in soluble sugars results in more available 
food for the yeast which breaks the carbohydrates down with the 
production of carbon dioxide, so necessary in the leavening of bread. 

"Water-soluble basic nitrogen decreased slightly in most flours 
as a result of ageing. This may be owing to an actual condensing of 
protein resulting in a more elastic gluten." 

25. Greaves, J. E., and Hirst, C, T. The influence of storage on the 
composition of flour. Utah Agr. Exp. 3ta. Tech. Bui. 19-4, (1925). 
C. A. Vol. 20, p. 2031 6 . 1926. *'- 

"The H-ion concentration in every flour examined first 

decreased and later increased. As deterioration set in there 
was increase in the H-ion concentration of the flour. No evi- 
dence was obtained by the Sorenson titration method -that protein 
cleavage occurs during storage. From 1.39 to 3.52 percent of 
the N of these flours occurred as water-soluble basic N. Soluble 
carbohydrates increased progressively during the storage period." 

26. Greaves, J. E. Changes in stored flour. American Miller, Vol. 54, 
p. 376,(1926). C. A. Vol. 20, p. 2031 7 . 1926. * 

"At the Utah Experiment Station there were stored thirteen 

50-lb. sacks of flour from December 1921 to January 1925 

The results indicate that it is only inferior flours which great- 
ly increase in acidity during four years' storage. There is a 
variation in the water-soluble reducing sugars found in different 
flours, and there is a tendency for the water-soluble carbo- 
hydrates to increase during storage. The water- absorption power 
of these flours increased considerably. Some of the flours yield- 
ed a loaf of greater volume after storage, whereas others 
registered a shrinkage. The results as a whole point to the con- 
clusion that the flours improve in brcadmaking properties on 
storage and that this benefit comes from ripening changes brought 
about by the action of enzymes on the carbohydrates, fats and 
proteins ." 



-;:- C. A. abstract checked with bulletin, 



10 



27. Gross, Emanuel. Changes in grain seeds during ten years of 
storage. Z. Landw. Versuchsw. Vol. 20, p. 4-71 (1917)^ 
Biedermann's Zentr. Vol. 48, pp. 395-4-00 (1919); C. A. Vol. 14, 
p. 2666 7 . 1920. 

Wheat, rye, barley, and oats were stored in beakers or in 

sacks in an air-dry unheated room Oats and barley increased 

in weight while wheat and rye had the same weight per hecto- 
liter The water content of barley decreased most, then oats, 

rye, and wheat. -Increase in dry weight on storage is explained 
by the fact that starch is converted to maltose and dextrin, 
which process utilizes water. 

28. Hale, W. S., Schwimmer, Sigmund, and Bayfield, E. G. Studies on 
treating wheat with ethylene: I. Effect upon high moisture wheat, 
Manuscript from Enzyme Research Laboratory. U. S. Dept. of Agr., 
Bur. Agr. Chem. and Eng. 1942. 

"As a rule, freshly harvested wheat neither bakes nor germinates 
well. A period of storage is necessary to bring either of these 
characteristics to the optimum level. Previously reported experi- 
ments /Balls and Hale (194-0) 7 have shown that wheat, harvested while 
somewhat immature, underwent an almost immediate increase in baking 
test and germination capacity when exposed to air containing traces 
of ethylene. On the other hand, the flour from immature wheat (be- 
fore treatment with ethylene) was not improved by subsequent ex- 
posure to the gas, although eventually it improved, like other fresh 
flour, on lengthy storage. Thus it seems the effect of ethylene on 
the baking test takes place in the whole grain. It is accompanied 
by a temporary rise in carbon dioxide output (frequently referred to 
as 'respiration'). Furthermore, the effect Is not particularly pro- 
nounced on grain already aged in storage." 

29. Hoyt, L. F. Further fumigation tests with ethylene dichloride — car- 
bon tetrachloride mixture. Ind, and Eng. Chem. Vol. 20, No. 4, 

p. 931. September 1928. 

"The food products after fumigation show different effects. 
Those rich in fat absorbed the fumigant appreciably but on exposure 
to the air gradually gave off the fumigant and became edible in 1 to 
8 days." 

Results of baking tests on Gold Medal flour showed, "There was 
no detectable difference in the odor, texture, or general appearance 
of these 'loaves, and although a faint odor of fumigant could be 
detected in the flour before use, the fumigant had had no effect on 
the quality of the gluten and could not be detected in the finished 
loaf." 



11 



Baking tests on whole-grain graham milled from fumigated grain 
indicated that "No odor of the fumigant could be detected in the hot 
loaf when broken open — the most severe test." 

30. Johnson, Arnold H., and Green, Jesse. Wheat and flour studies XVIII. 
A study of the nature of the acid responsible for the increase in 
acidity which occurs in flours during storage. Cer. Chem. Vol. 3, 
pp. 134-H5. 1931. 

"It has been known for a long time that flours increase in their 
acidity during storage . " 

"The H-ion concentration of water extracts of stored flours ex- 
tracted with ether were the same as those of the extracts of the 
freshly -milled flours. 

"The idea is expressed that other-extractable. acids arc alone 
responsible for the changes in H-ion concentration or in acidity 
(as measured by any method) which occur in flours during storage 
under proper conditions. 

"The acids removed from flour by extraction with ether must, 
on the average, have rather long carbon chains as their coefficient 
of distribution between water and ether Was of the order .014 to 1." 

31. Jones, D. Broesc, Divine, J. P., and Gersdorff, Chas. E. F. The 
effect of storage of corn on the chemical properties of its protein 
and on its growth-promoting value. Cer. Chen. Vol. 19, No. 6, 

pp. 819-830. November 1942. 

"The effects of storage of ground corn and of whole shelled 
corn upon the properties of the proteins and upon nutritive 
value were determined at various intervals over a storage period 
of two years. The results show that three different types of 
alterations in the proteins occur: (1) a decrease in the solu- 
bility of the proteins, (2) a partial breakdown of the proteins, 
indicated by a decrease in true protein content, and (3) a de- 
crease in digestibility. 

"The extent of the alterations is influenced by temperature, 
type of container, duration of storage, and nature of the material 
stored. Samples stored at 76° F. were affected more than those 
stored at 30° F., and those in bags more than those in sealed 
glass jars. Changes in the ground corn were greater than those in 
the whole shelled corn. The total nitrogen and free ammonia re- 
mained unchanged. The extent of denaturation of the proteins was 
measured by determination of solubility in 3 percent NaCl solu- 
tion, 70 percent alcohol, and 3 percent sodium salicylate. At 
the end of two years' storage in a bag at 76 Q F. the solubility of 
the ground-corn protein in NaCl solution and in alcohol was 



12 



approximately 60 percent less than that of fresh raaterial. The 
true-protein value and digestibility had decreased 32 percent and 
29 percent, respectively. Hie rates of the decreases were much 
more rapid during the early storage intervals than later. 

"Significant decreases in feeding value were also found. 
During -a 4-2-day feeding period the average gain in weight of 
albino rats fed with ground corn which had been stored for 6 
months in jars at 76° F. Tfas 63 g. in comparison with 34 g. for 
rats fed with fresh material, and 56 g. for rats fed with 
material stored for 12 months. The value remained the same at the 
end' of the second year's storage. In every instance less of the 
stored material than of the fresh material was consumed by the 
same number of rats in the same time. For material stored 6 months, 
the gain in weight per gram consumed was the same as for fresh 
material. For material stored 12 and 24 months, the gain in weight 
per gram consumed was less." 

32. Jones, D. Breese, and Gersdorff, Chas. E. F. The effect of storage 
on the protein of wheat, white flour, and whole wheat flour. Cer. 
Chem. Vol. 18, No. U, pp. 417-434. July 1941. 

"The effect of storage- under different conditions upon the pro- 
teins of white flour, whole wheat flour, and wheat kernels has been 
studied at various intervals over a period of two years. The re- 
sults show that three different types of alterations occur; (1) a 
decrease in the solubility of the proteins, (2) a partial breakdown 
of the proteins indicated by decrease in true protein contunt, by 
decrease in the amount of nitrogen precipitablc by trichloracetic 
acid, and by increase in amino nitrogen, and (3) decrease in 
digestibility. 

"The extent of the changes depends on temperature, type of con- 
tainers, duration of storage, and the nature of the material stored. 
Samples stored at 76° F. were affected more than those stored at 
30° F., and those in bags more than those in scaled jars. Changes 
in white flour were in general greater than in whole wheat flour. 
Significant changes occurred also in the wheat kernels, although not 
as great as in the flours. The- total nitrogen and free ammonia re- 
mained unchanged. The extent of denaturation of the protuins was 
followed by determination of solubility in 3 percent NaCl, 70 percent 
alcohol, and 3 percent sodium salicylate. The greatest decrease was 
found in solubility of the proteins of white flour in NaCT. When 
stored in a bag at 76° F. for two years the percentage decrease 
amounted to 61 percent, and 57 percent after similar storage in a 
sealed glass jar. The alteration of the proteins is ascribed to the 
effect of enzymes and oxidation." 



13 



33. Jones , D. Breese, and Gersdorff, Chas. E. F. Changes that occur in 
the proteins of soybean meal as a result of storage. Jour. Am. Chem. 
Soc. Vol. 60, No. 3, pp. 723-724. 1932. 

"Studies have been started to investigate the nature and extent 
of changes which occur in the proteins of seeds (both whole and 
ground) when stored under different conditions. Results thus far ob- 
tained show that marked changes in the chemical properties of the 
proteins of ground soybeans occur very soon after grinding. Some of 
these changes suggest a decrease in the biological value of the 
proteins . 

"By the end of six months the digestibility of the protein 

of the low-fat meal stored in bags at 76° had dropped nearly 19 per- 
cent below that of the meal when freshly ground. The greatest' 
changes occurred at 76° , although at 30° the changes were surprising- 
ly high. Greater changes occurred in the meals stored in bags than 
in those stored in sealed jars. Of interest is the consistently 
greater changes that occurred in the low-fat samples than in the high- 
fat samples. The total nitrogen and free ammonium content of all 
the samples remained constant throughout the storage periods. The 
high-fat samples showed a slight increase in free fatty acids, 
particularly in the samples stored at 76° . 

"Storage of soybean meal apparently results in partial de- 
naturation of the proteins as indicated by their decreased 
solubility in salt solution. A proteolysis is also indicated 
by the drop in true protein values. The nature of the marked 
decrease in digestibility in vitro is being studied." 

34. Jones, D. Breese, and Gersdorff, Charles E. F. The effect of 
storage on the proteins of seeds and their flours. Soybeans 

and wheat. Proc. Am. Soc. Biol. Chemists. Vol. IX, No. 1, p. xlix. 
1939. 

"Marked changes occur in the proteins of seeds on storage or 
ageing, the extent varying with the kind of seed and conditions 
of storage. Although occurring much more rapidly in flours or 
meals, these changes also take place in the unground seeds. 

"Defatted soybean meal stored for 1 year in bags at 24.4° 
decreased 18 percent in the amount of nitrogen extractable by 10 
percent NaCl solution, 21 percent in digestibility, and nearly 
12 percent in true protein value. Materially lower percentage 
changes occurred at - 1.1°. 

"Denaturation of the proteins of wheat and of wheat flours 
occurred to a much larger extent and more rapidly than that of 
the soybean proteins. After 1 month's storage in sealed jars 
at 24.4°, the nitrogen extractable from white flour by 3 percent 



14 



NaCl had decreased 43 percent. At the end of 1 year, the per- 
centage had dropped to approximately 50 percent. Large decreases 
in the amount of nitrogen extrac table with 70 percent alcohol and 
Na salicylate also occurred, with similar changes occurring in 
whole wheat flour. Indications of extensive proteolysis in the 
wheat flours were shown by increased values in amino nitrogen and 
decreases in true protein values .and in nitrogen precipitable by 
trichloracetic acid. 

"Changes also occurred in the whole, unground wheat kernels. 
After storage in jars at 24-. 4° for 9 months, the percentages of 
nitrogen extrac table by NaCl, alcohol, and sodium salicylate had 
decreased 26, IS, and 9 percent, respectively. Considerable 
proteolysis had also occurred." 

35. Kansas Agricultural Experiment Station Tech. Bui. 1. Milling 
and baking quality of wheat and flour, pp. 141-142. 1916. 

"When wheat undergoes the process of ageing, the gluten 
undergoes this desirable transformation. It becomes more elastic 
and pliable. The dough from flour made of such wheat is more 
easily handled, requires less fermentation and gives a loaf of 
larger volume and better texture. 

"It seems entirely possible that if wheat is treated with 

a certain amount of moisture and then subjected to heat for a short 
time this will have the same effect of natural ageing. The amount 
of moisture added should have a definite relation to the moisture 
content; the higher the moisture content the less the amount of 
water needed." 

36. Kelly, C. F., Stahl, B. M., Salmon, S. C, and Black, R. H. "tfheat 
storage in experimental farm-type bins. U. S. Dept. Agr. Cir. 

No. 637, 245 pp. 1942. 

"Various measurements were used to determine the quality of the 
wheat during the storage period. The external evidences of wheat 
deterioration (such as percent total damage, test weight, odor, etc.) 
usually were not apparent until the condition of the grain had been 
lowered enough to affect its commercial grade. However, percent 
germination and fat acidity of sound wheat were found to be valuable 
indices of incipient deterioration that is not apparent from grade 
examination, and graphs are presented to show the relation of percent 
total damage and percent germination to fat acidity through the 
range from 10 to 40 units of fat acidity." 



15 



37. Kozmin, Natalie P., Alakrenskaya, Katherin A., and Bondarev, Valerie 
D. "Ripening" of wheat flour and its biochemical basis. Muhlenlab. 
Vol. 4, pp, 16-32 (1934); C. a. Vol. 28, p. 6207 s . 1934- 

"Ripening of the gluten in stored flour causes an increase in 
elasticity; gluten of strong flours becomes even more elastic and 
short. The effect of storage varies according to the flour type. 
The real cause of ripening is the hydrolysis of the fat through the 
accumulation of considerable amounts (up to 1 percent) of free un- 
saturated acids — oleic, linoleic, linolenic. On removal of these 
acids by ether extraction aged flour is 'rejuvenated', i.e. the 
original character of the gluten is restored. Conversely the addi- 
tion of these acids to fresh flour has a marked ageing effect. 
Storage temperature is very important: at 12° -15° the production of 
free acids practically ceases ; at 45° the upper limit for the 
activity of fat-splitting enzymes is not yet attained. Fat hydroly- 
sis occurs independently of the supply of oxygen; in the presence of 
oxygen rancidity develops." 

38. Kozmin, Natalie P. The ageing of wheat flour and the nature of this 
process. Cer. Ch'em. Vol. 12, No. 2, pp. 165-171. March 1935. 

"During the storage of flour at a high temperature there could 
be observed a strong rise of titratable acidity as well as an in- 
crease in the acid number of fat. The content of the free acids in 
the fat of this flour amounted to almost 50 percent. 

"The removal of fat from the aged flour by ether extraction re- 
turned the gluten to its original quality, making it 'young' again." 

Conclusions of the experiments are: 

"During storage of flour a change in the quality of gluten in 
the direction of its strengthening has been observed. The direct 
cause of this change is the accumulation of free fatty acids in the 
flour, caused by a slow process of fat hydrolysis. The removal of 
fatty acids rejuvenates the flour, returning it to its original 
state. 

"In turn the addition of free unsaturated fatty acids produces 
the same effect as natural ageing. Free unsaturated fatty acids 
(oleic, linoleic, linolenic, etc.) influence the colloid behavior 
of gluten in a specific manner, thickening the gel. Saturated 
fatty acids with the same amount of carbon atoms (stearinic, 
palmitinic, etc.) show no such effect." (Author probably means 
stearic and palmitic acids). 

"The process of flour ageing proceeds without participation 
of oxygen, as fat hydrolysis does not require the presence of the 
same. Oxidation of flour pigments taking place during ageing has 



16 



no connection with the change of gluten quality." 

"Temperature is the most important factor influencing ageing 
of the flour." 

39. Kiihl, Hugo, and Kliefoth, D. Storage of wheat flour under different 
conditions. Muhlenlab. Vol. 4, pp. 65-70 (1934): 0. A. Vol. 23, 

p. 6207 6 . 1934. 

"Portions of the same flour, in one case unbleached and un- 
treated, and in the other electrically bleached and treated with 
KBrt>3, were stored 6 months in tightly packed cloth sacks and in 
the form of cylinders compressed at 300 atmospheres. The effect 
of admixture of 3 percent wheat germ, both natural and defatted, 
on flours thus stored was also determined. The keeping quality 
of flour during storage is in every way enhanced by compression 
into a solid mass. The keeping quality of flour is influenced 
by its fat content, even small admixtures of germ leading to rapid 
deterioration. Admixture of defatted germ has little or no effect. 
Flour treated with KErO.-a and electrically bleached does not keep so 
well as untreated, unbleached flour, and falls off somewhat in 
baking quality on storage." 

40. Kuhl, Hugo. The effect of long storage on flour. Mehl. u. Brot. 
No. 23, pp. 1-5 (1935); Chen. Zentr. Vol. 1, p. 912 (1936); 

C. A. Vol. 31, p. 5335-. 1937. 

"Storing the flour under a pressure of 300 atmospheres in- 
creased its keeping qualities. No moths developed during prolonged 
storage and no fungus mold proliferation and no musty odor were evi- 
dent. Untreated flour was more stable to storage than that treated 
with bromate or electrolytic ally bleached. The fatty acids of the 
embryo at first have a favorable, but after a long storage an un- 
favorable effect. Wheat embryos freed from their fatty acids by 
compression methods decidedly improved the baking qualities of flour 
stored for a long period and overcame the undesirable effects of 
treatment with bromate and bleaching. Discoloration appearing after 
a very long storage is due to the action of the oxidases." 

41. Ladd, E. F. Tempering of durum wheat; winter wheat versus spring 
wheat. N. Dak. Spec. Bui. Vol. 1, No. 36, pp. 414-415. 1911. 

See -reference number 46, this bibliography, for review. 



17 



42. Leavitt, ^herman, and Le Clerc, J. A. Change in the composition of 
unground cereals during storage. Jour. Ind. and Eng. Chem. Vol. 1, 
pp. 299-302. 1909. 

The authors found notable decreases in the percentage of sugar 
in corn which was stored for 2 years; barley and oats showed small 
decreases while wheat and rye changed slightly. Some samples of 
wheat showed an actual increase in sugar content. The other con- 
stituents changed very little or not at all. 

43. Le Clerc, J. A., Wessling, H. h. , Bailey, L. H., and Gordon, W. 0. 
Composition and baking value of different particles of flour. 
Operative Miller, Vol. 24, pp. 2 57-258. 1919. 

"The object of this investigation was to determine the difference, 
if any, in the chemical composition and likewise in the baking quali- 
ty of the various sized particles of which every flour is com- 
posed The following tentative conclusions may be drawn from the 

experiments, viz., that in most flours there are three almost dis- 
tinct grades t (1) A coarse portion; (2) A very fine portion; (3) A 
medium fine portion. It was also found: That less than one-fourth 
of the flour belongs to the coarse, one-third to the finest and the 
remainder or approximately one-half to the intermediate; that the 
quality of the coarse and very fine portions or separates is in- 
ferior to that of the intermediate; that the very fine granulate is 
by far the poorest part of the flour, both as regards the quantity 
and quality of the gluten and as regards the quality of the bread 
produced from It; that those portions which remain on the Nos. 18,20 
and 21 silks are very similar in gluten content and produce bread of 
equally high quality; that in every case the quality of the bread 
made from the intermediate granulates is superior to that of the 
original flour; that a superior br^ad flour could be made by select- 
ing only those granulates which show superior value." 

44. McCaig, J. D.^ and McCalla, A. G. Changes in the physical properties 
of gluten with ageing of flour. Can. Jour, of Res. Sec. C, Vol. 19, 
pp. 163-176. May 1941. 

"The pl-rysical properties of gluten, as determined by the hydra- 
tion of the gluten between pH 4 and 7, are deleteriously affected by 
ageing of flour. Similar effects are obtained by adding linolic acid, 
whereas some of the effects of ageing can be removed by extraction of 
the flour with ether. The original quality of the gluten is not 
restored by such extraction. Gluten from aged deteriorated flour 
swells enormously in 0.1N acetic acid; such hydration is not an indi- 
cation of good quality but rather of resistance to dispersion. Some 
freshly milled flours produce gluten possessing the physical charac- 
teristics of gluten from aged deteriorated flour. 



IS 



"It is concluded that the quality of gluten depends to a 
considerable extent on the nature of the absorbed lipoids. 
Many of the characteristics of gluten are determined by relative- 
ly insoluble (unidentified) lipoid substances, whereas the absence 
of such lipoids and the formation of fatty acids during ageing are 
deleterious to gluten quality." 

45. McCalla, A. G., McCaig, J. D. 3 and Paul, A. D, Effect of various 
conditions of storage on baking quality of flour. Can. Jour of 
Res. Sec. C, Vol. 17, pp. 452-459. 1939. 

- "Flour stored in sealers in a refrigerator at 2° C. did not 
change in quality for 22 months after milling. Similar flours 
stored in sealers at room temperature deteriorated significantly 
within three months, while a third lot stored in snail bags at 
room temperature showed first a definite improvement and then 
rapid deterioration. At the end of 22 months flours stored in 
sacks were much the poorest. Acidity of all flours increased 
with storage, but this determination was of little value in es- 
timating flour quality." 

4-6. Mangels, C. E. Effect of storage on baking quality of common 
and durum wheats . Cer. Chem. Vol. 1, No. 4, pp. 169-178. 
July 1924. 

"A general impression exists that both wheat and flour im- 
prove in storage, and this is probably true under certain con- 
ditions, A review of the literature indicates that studies on 
this point have been rather limited. 

"C. E. Saunders (1) V and Shutt (2), of the Ottawa station, 
studied the effect of storage on the baking quality of wheat end 
flour. Saunders found that both wheat and flour improved in water 
absorption and in shape of loaf when stored over long periods. 
The author also states 'In regard to loaf volume some irregulari- 
ties occurred for which no satisfactory explanation can be 
offered at present. ' 

"Shutt made chemical studies on the wheat and flour samples 
used by Saunders and found that total protein and gliadin tend 
to increase in storage but the difference is hardly sufficient to 
be of significance. No durum wheats were used by Saunders and 
Shutt. Saunders in a later report (3) gives the following conclu- 
sions: 'The table and outline drawings show clearly that most of 
these varieties of wheat are improved very considerably in baking 
qualities by long storage, either as wheat or as flour. The highest 



1/ Figures in parentheses refer to "bibliography", p. 20 



19 



baking strength was attained when the wheat was stored about three 
or four years. When the material was stored as flour the changes 
were more rapid and the highest baking strength was reached in two 
or three years. It appears that by storing the material as flour 
a higher bakings trength can be obtained than is possible when the 
material is stored as wheat. Ultimately deterioration sets in 
rather earlier with the flour than with the wheat, but it is evi- 
dent that storage under good conditions is safe for at least ten 
years.' The author also states, 'In spite of all the precautions 
taken the results show a number of provoking irregularities,' and 
these irregularities are ascribed to variation in quality of yeast. 
The wheat and flour samples in this case were stored in an unheated 
room. 

"Snyder (4) stored flour milled from spring and winter wheat in 
a dry, we 11- ventilated warehouse, four, eight, and twelve months, 
and compared the stored flour with fresh flour milled from similar 
wheat. Analyses and baking tests indicated that flour stored under 
these conditions shows no deterioration in quality, and a slight im- 
provement x;as noted in size and color of loaf. 

"Swan's on, Willard, and Fitz (5) stored flour in steam heated 
and unheated rooms for comparatively long periods. They find loss 
of moisture, but otherwise no significant change in baking quality 
or composition. 

"Stockham (6) reports improvement in baking quality of flour 
stored in a humid cabinet at 85-95° F. for three "weeks as compared 
with original and with flour stored in a dessicator over sulphuric 
acid. 

"Ladd (7) reports results of a storage test with durum patents 
and clears. These flours were stored for three months during hot 
summer weather (May 17 to August 17, 1911). Six out of seven 
samples show a loss in volume, but absorption was higher for all 
samples, and color of the clear flours showed marked improvement. 

"H. L. White (S) found that flour stored for two years showed 
no considerable increase in acidity. The hard "wheat flours main- 
tained their baking qualities better than the durum flours, but both 
showed decrease in volume ." 

Conclusion is that warm storage is more detrimental to flour 
quality than cool storage. After 11 months' storage, all lots of 
flour showed some deterioration, but the durum flours showed 
relatively greater deterioration than the common wheat flours. 



20 



Bibliography 

"1. (a) Canadian Experimental Farms Report 1907, 
pp. 219-223. 

(b) Canadian Experimental Farms Report 1909, 
pp. 204-208^. 

(c ) Canadian Experimental Farms Report 1910, 
pp. 167-170. 

2. Canadian Experimental Farms Report 1911, pp. 163-171. 

3. Bulletin 97, pp. 28-38. Department of Agriculture, 

Dom. of Can. (1921). 

4. Minnesota Agricultural Experiment Station Bulletin 35, 

pp. 213-217. (1904). 

5. Kansas Agricultural Experiment Station, Bulletin 202, 

p. 133. (1915). ' 

6. North Dakota Special Bulletin. Vol. 2, No. 7, 

p. 113. (1912). 

7. North Dakota Special Eulletin. Vol. 1, No. 36, 

pp. 414-415. (1911). 

8. North Dakota Report of Food Coiiimissioner, pp. 140-143- 

(1911)." 

47. Miege. The maturing of wheat and flour. Compt. rend. acad. 
agr. France. Vol, 19, pp. 636-9 (1933); C k. Vol. 27, 

p. 4314 3 . 1933. 

"The effects of various types of storage on wheat and 
flour have been determined. The methods of storage tested have 
been: in bags, in bulk, kept covered at a temperature of 21°, 
in the air, day and night and in hermetically sealed bottles. 
Storage in bulk in the air causes a general improvement of the 
quality of the wheat. This is due to a slow oxidation of the 
grain reserves which causes a diminution of the carbohydrates 
and a modification of the physical properties of the gluten. 
Under these conditions there is a lowering of the specific 
gravity and an increase in the moisture of the grain. Tenacity 
and baking value are greatly improved by storage." 

48. National Association of British and Irish Millers Ltd. Corres- 
pondence between London representative of U. S. Department of 
Agriculture and the Association regarding transactions relating 
to "old" wheat. 1931-1932. 

In 1931, the fact that United States wheat offered for sale 
by the Farm Board was one or two years old was one of the rea- 
sons advanced by the National Association of British and Irish 
Millers for refusing to accept future deliveries of United States 
wheat on a grade basis with grade certificate being prima facie 
evidence that delivery was of condition and quality contracted 
for. 



21 



49. Northwestern Miller. Wheat gets sick. Northwestern Miller. 
Vol. 209, No. 2, p. 18a. January 14, 1942. 

"In a recent issue of The Piedmont Bulletin, official publica- 
tion of the Piedmont Millers Association, some comments on 'sick 
wheat' by Charles Molin, supervisor of the Virginia Division of 
Markets, are presented." 

"Mr. Molin points out that moisture has been an important factor 
in the grading of the 194-1 wheat crop in Virginia and expresses the 
opinion that some wheat went into storage in mill and farm granaries 
with moisture contents higher than normal. The warm weather of the 
summer extended well into the fall, and much of the autumn went by 
without the occurrence of any considerable cold weather. Such con- 
ditions are regarded as furnishing excellent opportunity for the 
development of 'sick wheat', and the writer emphasizes the dangers 
attending the storage of grain with a moisture content of 14 per- 
cent or above. 

"Attention is called to the necessity of dissipating the heat 
stored in the grain as a result of summer temperatures. It is rec- 
ommended that wheat should be cooled to 60° F., or lower, as quickly 
as possible, by 'turning' it and passing it over separators, or by 
some other means which subjects it to thorough aeration. 

"It is pointed out that at temperatures above 60° there is like- 
ly to be insect infestation, and that with the rise in temperature 
accompanying infestation, the development of sick wheat will progress 
rapidly . 

"In describing 'sick wheat' , Mr. Molin brought out that 'bin 
burnt' indicates a late stage of 'sickness'. It is stated that bin 
burnt wheat is unsuitable for milling if the production of good 
flour is the objective. Continuing the description, Mr. Molin said, 
'The ash and acidity of the flour /from bin burnt wheat / is in- 
creased and the quality markedly decreased. However, the good flour- 
making properties of wheat have been adversely affected by the 
development of sick wheat long before the bin burnt stage is reached.' 

"The germ of a healthy kernel is then described as a fatty sub- 
stance, the extraction of which from the floury parts of the grain 
is dependent upon the flattening of the germ into disc-shaped bodies. 
These bodies may be separated from the floury products . ' In sick 
wheat', the writer continues, 'the germ tends to pulverize rather 
than flatten, and separation is difficult if not impossible. The 
germ becomes slightly depressed, and the coating, of a grayish-brown 
appearance, rather difficult to detect unless one is on the lookout 
with an experienced eye.' 



22 



"'If the germ coating is delicately peeled off, the dark-brown 
to black powdery appearance of the germ underneath, which has little 
resemblance to a healthy germ, may be seen. The general appearance 
of such wheat to a casual observer is good, but its milling quali- 
ties are disappointing.'" 

50. Nature. Storage of National Wheatmeal. Nature, Vol. 149 3 No. 3788. 
June 6, 1942. 

"A report on the problem of the storage qualities of National 
wheatmeal has been published by the Research Association of British 
Flour-Millers in Milling of May 23. Storage trials were carried 
out over a period of a year and included not only laboratory experi- 
ments but also tests under commercial conditions in mills, bakeries 
and buffer depots. Moisture content is the most important factor 
determining storage life: thus at 14, 14-1/2 and 15-1/2 percent mois- 
ture contents, provided the storage conditions are good and a sound 
wheat grist is used, the wheatmeals will keep in good condition for 
9 months, 4-6 months and 2 months, respectively. Temperature is a 
further factor, and whereas at 60° F. a wheatmeal of 15-1/2 percent 
moisture remained in good condition for 11 weeks, at 77° F. it kept 
only for 3-4 weeks . An additional point of importance revealed by 
the experiments is that National wheatmeal is more prone to insect 
infestation than white flour." 

51. Oklahoma Agricultural and Mechanical College. Agronomists experi- 
ment with fumigants for farms. Northwestern Miller. Vol. 211, 
No. 8, p. 16. August 19, 1942. 

Agronomists from the Oklahoma Agricultural and Mechanical 
College have experimented with carbon disulphide as a fumigant. 
Because of its extremely high inflammable and explosive proper- 
ties it is used for fumigation principally in a mixture with 
other fumigants or alone on a farm for treatment of grain in 
isolated bins . Workers found that the agent has no significant 
effect upon the germination or baking quality of wheat unless 
concentrations exceeding four times the recommended rate of approxi- 
mately 4 gallons per 1,000 bushels are used. The agronomists state 
further that treatments heavy enough to affect germination also 
reduced loaf volume and changed the characteristics of the dough. 

52.. Parker, John H. wheat quality as affected by farm storage. 

Northwestern Miller. Vol. 177, No. 2, p. 118. January 10, 1934. 

"Storage damage in wheat is a serious problem at least one 
year in five on the average, even in a relatively dry 'wheat grow- 
ing area such as central Kansas. 

"In general it may be said that wheat with 13 percent or 
less moisture will not be damaged by heating in storage, while 



23 



that with 14- percent or more moisture is likely to be damaged. 
This line is not a sharp one^ and will vary with temperature and 
humidity of the air and other factors." 

53. Phillips, C. Louise. Heating and spoiling of grain. Part I. Ab- 
stracts and references. U. S. Dept. Agr. Bur. Markets and Crop. 
Est. Ivlimeo. pp. 1-22. 1921. 

54. Phillips, C. Louise. Heating and spoiling of grain. Part II. Ab- 
stracts and references. U. S. Dept. Agr. Bur. Markets and Crop Est. 
Kimeo. pp. 23-41. 1921. 

55. Phillips, C. Louise. Respiration of grain, and its relation to the 
heating of grain. Sweat in wheat and flour. Abstracts and 
references. U. S. Dept. Agr. Bur. Ag. Econ. Hirneo. 7 pp. 1922. 

56. Phillips, 0. F. See reference number 22, this bibliography. 

57. Piettre, Maurice. Maturation of grains of wheat.; influence of cer- 
tain physicochemical phenomena. Compt. rend. Vol. 198, pp. 608-611. 
1934. C. A. Vol. 28, p. 2421 6 . 1934. 

The maturation of green wheat grains stored at -5° to -7° is 
characterized by a rapid decrease within 4 days, of reducing and 
nonreducing sugars, and within 8 days, of globulin and albumin, 
coincident with a rapid decrease in water. 

58. Rams tad, Paul E and Geddes, W. F. The respiration and storage be- 
havior of soybeans. Minn. Agr. Exp. Sta. Tech. Bui. 156. 1942. 

"The lowest moisture content at which soybeans were observed to 
heat was 15.6 percent. Increases in respiration with time of 
storage were marked in soybeans containing over 13 percent moisture 
when stored at room temperature; furthermore, the iodine number of 
oil from such beans was greatly reduced, although the quantity of oil 
did not seem to be diminished. Soybeans remained sound and retained 
their viability well at a moisture content of 15.8 percent for a year 
and a half when stored at 4° C. On the other hand, when stored at 
room temperature, viability 'was seriously diminished even below a 
moisture content of 10 percent." 

"Rapid loss of viability was caused by conditions which favored 
the growth of microorganisms in soybeans. Viability was better re- 
tained in beans stored at 15 percent moisture and a temperature of 
4° Q. than in beans from the same lot stored at 9 percent moisture 
and room temperature. To retain high maximum germination capacity, 
soybeans should be stored at a low moisture content (approximately 
10 percent) and at as low a temperature as feasible." 



24 



59. Robertson, D. W. , Fifield, C. C, and Zeleny, Lawrence. Milling, 
baking, and chemical properties of Colorado-grown Marquis and 
Kanred wheat stored 9 to 17 years. Jour. Am. Soc. Agron. Vol. 31, 
pp. 851-856. 1939. 

"Milling and baking tests were made with eight samples of 
Marquis wheat and three samples of Kanred wheat stored at Fort 
Collins, Colorado, in a dry, unheated room for periods up to 
17 years. There was a definite and fairly regular increase in 
fat acidity with storage, indicating a certain amount of 
progressive deterioration on storage. Satisfactory flour yields 
were obtained in all cases and unusual tempering was not re- 
quired in any case. All lots made satisfactory bread, there 
being no indications of deterioration in baking quality in any 

of the samples There was no apparent relation between 

deterioration in viability as shown by germination tests and 
baking quality." 

60. Robertson, D. "17., and Lute, Anna M. Germination of seed of farm 
crops in Colorado after storage for various periods of years. 
Jour. Am. Soc. Agron. Vol. 29, pp. 822-834. 1937. 

"Germination tests were made on the seeds of various farm 
crops adapted to Colorado conditions which had been stored in a 
dry, unheated room for periods varying from 1 to 15 years. 

"The germination percentage of wheat, oats, and barley de- 
clined slowly for the first 10-year period with a sharp break 
in germination between the 10th and 12th years. The drop in 
germination was as great or greater from the tenth to the 
fifteenth year as it was from the first to the tenth year." 

61. Robertson, D. W. , Lute, A. I.:., and Gardner, Robt. Effect of 
relative humidity on viability, moisture content, and respiration 
of wheat, oats, and barley seed in storage. Jour. Ag. Res. 

Vol. 59, pp. 281-291. 1939. 

"The data showing the rates of change of moisture and vi- 
ability with humidity offer a means of predicting the maximum 
time which would be safe for storage under any given relative- 
humidity, assuming temperature conditions comparable to those of 
the experiment." 

62. Rusca, Ralph A., and Gerdes, Francis L. Effects of artificially 
drying seed cotton on certain quality elements of cottonseed in 
storage. U. S. Dept. Agr. Cir. No. 651, p. 16. July 1942. 

"The conditions under which cottonseed is stored have an im- 
portant bearing on the quality of the seed after prolonged periods 
of storage. Excessive moisture content and overheating of the 



25 



seed not only have an ultimate adverse effect on the quality of oil 
extracted from stored seed but they may also influence its germina- 
tive properties." 

"Results of the 2-year study, in which 23 cottons were used, 
have been compiled and analyzed. They indicate that with green, 
damp, or wet seed cottons, the process of artificially drying before 
ginning did not cause an increase in the rate of deterioration of 
the seed in storage; that in fact, it caused retardation of the 
formation of free fatty acids. The higher the drying temperature 
used, the less was the free fatty acid content of the seed at the end 
of the 90-day storage period." 

"Germination tests on the undried and dried seed indicate that a 
free fa.tty acid content of 2 percent becomes critical as far as 
cottonseed germination is concerned." 

63. Saunders, C. E. Canadian Experimental Farms Report 1907, pp. 219-223. 
See reference number 46, this bibliography, for review. 

6/+. Saunders, C. E. Canadian Experimental Farms Report 1909, pp. 204-208. 
See reference number 4-6, this bibliography, for review. 

65. Saunders, C. E. Canadian Experimental Farms Report 1910, pp. 167-170. 
See reference number 46, this bibliography, for review. 

66. Saunders, C. E. Dept. of Agr. Dom. of Can. Bui. 97, pp. 23-38. 1921. 
See reference number 46, this bibliography, for review. 

67. Sayre, J. D. Storage tests with seed corn. Ohio Jour. Sci. Vol. 4-0, 
pp. 181-5 (1940); Exp. Sta. Rec. Vol. 85, p. 341. 1941. 

"Kernels of Clarage corn, sealed in glass tubes and containing 
18 percent moisture, remained viable after 6 years when stored at 
temperatures below freezing but died in less than 6 months at room 
temperature (about 30° C.) When stored at about 30° C. kernels 
stored in oxygen died in 3 years and in nitrogen or carbon dioxide 
decreased noticeably in germination, whereas those stored at low- 
temperatures in these gases or air gave good germination after 5 
years." 

68. Sharp, Paul Francis. Wheat and Flour Studies II. Ageing I. The 
change in hydrogen-ion concentration of wheat and mill products 
with age. Cer. Chem. Vol. 1, No. 3, pp. 117-132. 1924- 

"The hydrogen-ion concentration of ground wheat increases more 
rapidly than that of unground wheat." 



26 



69. Shellenberger, J. A. Variation in the baking quality of wheat during 
storage. Cer. Chem. Vol. 16, No. 5, pp. 676-682. September 1939. 

"The baking quality of "wheat is improved by storage after harvest , 
but the betterment observed during this investigation was not 
particularly impressive. This conclusion is based on the study of 
four classes of wheat, obtained from eight states, during the 1938 
harvest. 

"The experimental baking test, applied to new "wheat, provides a 
reliable indication of the potential baking quality of the crop. 

"There appears to be a direct relationship between the viability 
of wheat and its baking quality." 

70. Shollenberger, J. K., and Marshall, W. K. The effect of storage on 
the baking strength of wheat and flour. Unpublished report of mill- 
ing investigations. U. 5. Dept. of Agr. Bur. Agr. Econ. 1925. 

"The baking results on flours stored in tin cans do not in- 
dicate that the length of storage had any appreciable effect upon 
the baking strength of the flour. The chemical data on these flour 
samples showed a gradual loss in moisture and a tendency to increase 
in acidity and water-soluble nitrogen. The proportion of gliadin 
to gluten increased while the wet and dry gluten decreased during 
the latter part of storage. This decrease in gluten may have been 
due to some enzymic action "which decreased its cohesiveness thereby 
preventing its full recovery in "washing." 

The flours stored in cotton bags shewed marked changes in 
baking strength and chemical composition in the latter stages of 
storage . 

The authors state, however, that, "The results of these storage 
tests, it is believed, do not point to any very definite conclusions. 
In order to obtain more definite conclusions, it would be necessary 
to conduct experiments in which the moisture content of the wheat 
can be controlled during storage and in a room secure from "weevil 
infestations." 

71. Shutt, F. T. Influence of age on wheat and flour. Canadian Ex- 
perimental Farms Report 1911, pp. 168-171. 

See reference number 4.6, this bibliography, for review. 



27 



72. Simpson, D. M. Relation of moisture content and method of storage 
to deterioration of stored cottonseed. Jour. Agr. Res. Vol. 50, 
pp. 4-4-9-456. 1935. 

"Storage experiments with sea-island and upland cottonseed 
under the humid conditions prevailing at James Island, South 
Carolina, showed that in ordinary storage cottonseed deteriorates 
rapidly after two years. A definite relation is indicated between 
the moisture condition of the seed during storage and the rapidity 
of deterioration. Sea-island seeds, with a moisture content 
reduced below 8 percent, when stored in tin containers to prevent 
the rapid reabsorption of moisture, retained their germination per- 
centage with only slight improvement for 4-1/2 years. Upland cotton- 
seed stored under various conditions and containing from 8.7 5 to 
13.78 percent moisture deteriorated rapidly when the moisture in the 
stored seed remained above 10 percent. Dried seed stored to prevent 
reabsorption of moisture showed only slight deterioration after 2-1/2 
years. Seeds containing 13.73 percent moisture and stored to prevent 
drying were all dead nine months after the beginning of storage." 

73. Sinclair, A. T. , and McCalla, A. G. The influence of lipoids on the 
quality and keeping properties of flour. Can. Jour. Res. Sec. C, 
Vol. 15, pp. 187-203. May 1937. 

"The keeping properties of different flours varied considerably. 
Ageing was accompanied by increased absorption regardless of whether 
the flour deteriorated in baking quality. Increased acidity 
developed in all flours, but was not a good measure of deteriora- 
tion. Storage in sealed containers favored acidity increases, while 
storage in sacks favored deterioration. A decrease in ether extract 
accompanied deterioration, while decrease in the less soluble 
lipoids appeared to take place in all samples. 

"The changes in physical properties of gluten gave the best in- 
dication of deterioration. Gluten from deteriorated flour was harsh, 
spongy and short, and could not be completely dispersed in sodium 
salicylate. Unsaturated fatty acids added to flour had the same- 
effects on gluten, but not on baking quality. Ground wheat germ 
added to deteriorated flour Improved the gluten and restored its 
solubility. The more insoluble germ lipoids were the effective sub- 
stances. Alcohol extraction of flour caused deterioration, but 
gluten quality was largely restored by addition of germ. All results 
indicate the lipoids are absorbed on the protein of the gluten. 

"It is concluded that the unique physical properties of gluten 
are to a considerable extent dependent on the relatively insoluble 
lipoids present. The possibility of gluten denaturation being a 
breakdown of the protein-lipoid complex is discussed." 



28. 



74. Smith , W. D. and others. Artificial drying of rice on the farm. 
U. S. Dept. Agr. Cir. No. 292. 1933. 

"A drying air temperature of 120° F. can be used without injury 
to the rice if the moisture content is reduced only about 2 percent 
at each drying operation and the rice is allowed to remain in 
storage from 12 to 14 hours between dryings." 

75. Snyder, Harry. Yftieat and flour investigations. Minn. Agr. Exp. Sta. 
Bui. 85, pp. 213-217. 1904. 

■• See reference number 46, this bibliography, for review. 

76. Stockham, W. L. Improvement of flour in storage. N. Dak. Spec. 
Bui. Vol. 2, No. 7, p. 118. 1912. 

See reference number 46, this bibliography, for review. 

77. Swans on, A. F. Long time storage of winter wheat. Jour. Am. Soc. 
Agron. Vol. 31, No. 10, pp. 896-97. October 1939. 

Milling and baking investigations on 11-year old wheat apparent- 
ly stored when thoroughly dry and of low moisture content, free 
from weevils, and relatively free from cracked grain indicated 
that the wheat milled satisfactorily, that it baked a good loaf of 
bread, and that the flour gave a dough with a long mixing time and 
excellent milling tolerance. The milling and baking results com- 
pared favorably with those of the adapted varieties grown in the 
same region in 1933. 

78. Swanson, C. 0. The milling and baking qualities of a dead wheat. 
Northwestern Miller. Vol. I46, p. 154. April 14, 1926. 

In referring to wheat which had been stored under favorable 
conditions for 25 years, the author states: 

"These dead kernels may appear plump and sound, and according 
to the milling tests on this dead wheat they may yield a normal 
amount of flour. Such dead kernels, however, may increase the per- 
cent of ash in the flour and the flour has little value in baking 
beyond being a filler." 

79. Swanson, C. 0. VJheat and flour quality. Burgess publishing Co. 
227 pp. 1938. 

"A seed may die and yet the enzyme activity, although reduced, 
will persist for a considerable time after the life principle leaves, 
like the tools of a mechanic which remain after he is gone. 1'he 
diastatic activity of a sample of wheat 42 years old, which had been 
dead a long time, since wheat usually dies in less than 10 years, 



29 



was found to be 122 milligrams maltose per 10 grams of wheat. Many- 
samples of live wheat often give less maltose than this." (p. 83) 

"As a rule flour is stored for much shorter period than wheat 
and from what is known it is evident that flour does deteriorate 
much more rapidly than wheat. It has already been noted that when 
the wheat kernel is crushed the enzymes have a greater opportunity 
to act on the substrate. The fat in flour is also more exposed to 
effects of oxidation. Long storage of flour has shown an increase 
in hydrogen-ion concentration. It is generally considered that 
flour improves some in baking value after the first few weeks of 
storage. Some of these improvements are probably related to the 
changes which take place in the lipoids. (p. 126) 

80. Swanson, C. 0. Some factors involved in damage to wheat quality. 
Cer. Chen. Vol. 11, No. 2, pp. 173-199. March 1934- 

"One of the best measures for the extent of damage which has 
taken place in wheat Is the determination of the amount of acidity 
which has developed in the wheat fat. This is designated as 
rancidity. The development of this condition Is, however, related 
to the air supply. In the entire exclusion of air this will not 
develop. Hence the conditions which favor the development of mold 
and rancidity are closely related. However, since damage to quali- 
ty also took place in the sealed bottles, absence of high rancidity 
is not proof of lack of damage. 

"Sugar was not increased until the moisture was above 10 per- 
cent. The diastatic activity was not increased by high moisture; 
on the contrary, the diastatic activity was greatest in the samples 
stored with low moisture. Thus it is not possible to increase 
either the sugar content or the diastatic activity by adding water 
in amounts which are safe for storage or in .amounts used in temper- 
ing wheat." 

81. Swanson, C. 0. The ever-changing wheat — and the principles of its 
handling. Northwestern Miller. Vol. 195, p. 21. September 14, 1938. 

""While the exact relationship between loss in viability, u r 
germinating power, and quality have not been as extensively demon- 
strated as would be desirable, the following statements may be made. 
If wheat has a high percent of viability, it has not suffered any 
damage due to storage conditions. If the viability is low, it has 
suffered some damage, somewhat in proportion to the loss in viability. 
If a wheat is dead, the damage may be considerable. The deteriora- 
tion in quality, however, does not stop when the 'wheat dies. Hence, 
how seriously it is damaged depends on how long it has been dead. 
Then it depends on the quality of the wheat at the beginning of 
storage . " 



30 



82. Swanson, C. 0. The effect of low temperature in preventing damage 
to wheat stored with high moisture content. Cer. Chem. Vol. 18, 
No. 3, pp. 299-315. May 1941. 

"There was no decrease in viability in the samples stored in 
the cold (4-1° F.), while all those stored at higher moistures in the 
laboratory were dead. Wheat of good viability shows no damage to 

its milling and baking qualities Wheat may be stored at 41° F. 

at high moisture for many months without suffering any damage to its 
milling and baking qualities. When wheat has good viability it 
has suffered no damage to the gluten structure even when a slight 
odor indicating unsoundness could be detected." 

83. Swans on, C. 0. Effects of moisture on the physical and other 
properties of wheat. Cer. Chem. Vol. 18, No. 6, pp. 705-729. 
November 1941. 

Results from exposing wheat before threshing to various 
amounts of moisture and also from wetting threshed wheat grain 
to various moisture percentages from one to six times show that 
the greatest apparent effects were a lowering of test weight and 
a decrease in vitreous condition. The hardness as determined by 
the barley pearler was also decreased. Since these properties 
are important grain grading factors, wetting wheat either arti- 
ficially or by exposure to rain or by adding water to the grain 
and then drying did seriously affect the grading values of the 
grain. 

"The decreases in test weight were not reflected in corres- 
pondingly lower flour yields in the samples wetted after threshing. 
The samples wetted as grain, the test weights of which had been 
reduced as much as 6 pounds, gave essentially as high flour yields 
as the samples not wetted or those wetted comparatively little. 
This was not due to closer milling, since the ash figures varied 

only within the experimental limits Because there was no loss 

of material, there should have been no decrease in flour yield 
simply because the space occupied by the kernels in the test 
kettle had been increased. 

"The baking values obtained on representative samples did not 
correlate with the commercial grade of the grain nor with the 

severity of the treatment The curves made on the recording 

dough mixer showed a longer time of development and a decrease in 
height as a result of the more severe treatments." 

84. Swans on, C. 0., and Fenton, F. C. The quality of wheat as affect- 
ed by farm storage. Kansas Agr. Exp. Sta. Tech. Bui. 33. 1932. 

Tables are given showing the effect of damage resulting from 
storage on the chemical composition of wheat. 



31 



85. Swanson, C. 0., Willard, J. T. , and Fitz, L. A. Kansas flours; 
Chemical, baking, and storage tests. Kansas Agr. Exp. Sta. Bui. 
No. 202, p. 133. 1915. 

See reference number 46, of this bibliography, for review. 

86. Thomas, R. C. The role of certain fungi in the "sick wheat" problem. 
Ohio Bimonthly Bui. Vol. 22, No, 185, pp. 43-45. 1937. 

"It is evident from this study that there is a great difference 
in the toxic effect of the byproducts of growth of various fungi, 
including molds, upon the viability of wheat. All of the organisms 
used have been found to be commonly associated with grains both in 
the field and in storage. This association becomes significant only 
when the moisture content of the grain is high and the temperature 
favorable for mold growth. Two strains of ;i.spergilli have been 
found to elaborate toxic products when grown upon bran. The toxicity 
of these products was demonstrated by the reduction of viability of 
normal wheat. What further changes these molds may cause in bring- 
ing about the condition known as 'sick wheat', rendering the grain 
inferior and milled products below standard, remain to be seen." 

87. U. S. Dept. Agr. Clip Sheet No. 1253. Store soybeans dry. Release 
July 5, 1942. 

"Soybean seed stored in bulk sometimes loses viability — the 
ability to sprout — to a serious extent. Tests by the U. S. D. A. in 
different regions indicate that this is mainly a matter of controll- 
ing the storage temperature and seed moisture. One lot of soybean 
seeds with 8 or 9 percent moisture, held at 35° F. for 8 years 
suffered no loss in viability, whereas another batch, with 13 or 14 
percent moisture, held at 70° P., showed no germination after 20 
months . " 

88. Wallaces' Farmer and Iowa Homestead. Don't give steers old feed, 
p. 3. April 13, 1942. 

"Feeding beef steers exclusively on hay and corn that are 
several years old is now regarded as an unwise practice. Such feeds 
may have depreciated so much in vitamin content that the animals will 
develop edema, or swelling of the legs and quarters. Such affected 
animals may be condemned when shipped to market, and often sone will 
die in the feed-lot." 

The Illinois Experiment Station also reports that beef cattle 
fed on three and four-year-old corn thrive well for some time, until 
their front legs begin to swell. Lameness, loss of appetite and 
rapid loss of flesh are other symptoms. 



32 



Chemical analysis of old yellow corn by Illinois Experiment 
Station workers has shown Vitamin A content only half as great as in 
new corn. 

89. White, H. L. N. Dak. Report of Food Commissioner , pp. 140-14-3. 1911. 

See reference number 4-6, this bibliography, for review. 

90. Zeleny, Lawrence, and Coleman, D. A. Acidity in cereals and cereal 
products, its determination and significance. Cer. Chem. Vol. 15, 
pp. 580-595. 1938. 

"The Bureau of Agricultural Economics, in an effort to improve 
existing methods for evaluating quality of the cereal grains, has 
been making a study of acidity as a possible practical indication of 
deteriorative changes occurring in the grain." 

"The acidic substances present in cereals and cereal products 
may be divided into three principal classes: (1) free fatty acids 
(2) acid phosphates and (3) amino acids. These acids are present in 
small quantities in all normal grain and under certain conditions 
increase in amount chiefly by virtue of the enzymatic hydrolysis of 
fats, phytin, and proteins, respectively." 

"A study of the individual acidity fractions in 24-6 samples of 
corn and of the same fractions in wheat undergoing deterioration in 
storage reveals the fact that only the fat acidity increases 
significantly during the early stages of spoilage." 

"Fat acidity alone appears to be a more reliable index of sound- 
ness in grain than either of the 'other types of acid present, or than 
any combination of these acid fractions as determined by any of the 
commonly used methods." 

91. Zeleny, Lawrence. Fat acidity in relation to heating of corn in 
storage. Cer. Chem. Vol. 17, pp. 29-37. 194-0. C. A. Vol. 34 , 
p. 2090. 194-0. -::- 

"The rate at which heat is developed depends upon the moisture 
content of the grain, the temperature, the available 02 supply, and 
upon certain characteristics of the grain itself, which are not 
completely understood. The acidity of grain, particularly of corn, 
is a more reliable measure of its degree of soundness than other 
available chemical or physical tests. Fat acidity is expressed in 
terms of mg. of KOH required to neutralize the free fatty acids 
extracted from 100 g. of corn calculated to a dry matter basis. 
The rate of spontaneous heating of grain can be predicted much more 



C. A. abstract checked with Cer. Chem. publication. 



33 



accurately when moisture and fat acidity are considered together than 
with moisture alone. It was shown that corn with a moisture content 
of 17 percent and a fat acidity of 100 can be expected to heat in 
storage as rapidly as corn with a moisture content of 21 percent and 
a fat acidity value of 20." 

92. Zeleny, Lawrence. Milling deteriorated wheat. Am. Miller Vol. 69, 
No. 11, pp. 34-37. November 194-1. 

Deterioration is measured by amount of free fatty acids. 

"The Agricultural Marketing Administration is developing another 
type of test that may prove to be of value as an index of wheat and 
flour deteriorations. This test is designed to measure gluten pro- 
tein in either wheat or flour by a method that utilizes the photo- 
electric cell or so-called 'electric eye. 1 The method is considerably 
simpler than the conventional Kjeldahl test and has the distinct 
advantage of being a measure of gluten protein rather than total 
protein content. Deterioration of wheat or flour in storage is fre- 
quently accompanied by a degradation of the gluten. This test is 
still in the developmental stage." 



34 



INDEX 



Item 



Item 



Acid 






Compression 






Amino 




90 


Effect of 




39,40 


Fatty 4,37 


,44 


,62,73,90,92 


Container 






Linoleic 




37 


Effect of 




8,15,27,32 


Linolenic 




37 






39,45,47,73 


Linolic 




44 


Corn 




5,14,18,31 


Number 




38 






42,90 


Oleic 




4,37 


Cottonseed 




62,72 


Phosphate 




90 








Acidity 






Damage 






Corn 




6 


Heat 




10,21,22,52 


Cottonseed 




.- 62 


Dead kernels 




78,81 


Flour 16 


,17 


,26,30,38,45 


Deterioration 




14,92 






46,59,70,73 


Dextrin 




27 


Grain 




90,91 


Diastatic activity 


SO 


Wheat 




36,49,80 


Digestibility 






Aging 




20,35,59,77 


Flour 




32 


Amino 






Drying 




12,62,74,83 


Acid 




90 








Nitrogen 




32 


Edema 




88 


Ash 




49,78 


Ethylene gas 




3,20,28,29 


Aspergilli 




86 


Enzyme 












Enzymic acti 


on 


7,21,24,26 


Bacteria 




4 






32,79,90 


Baking quality 


(See Quality) 








Barley 




27,42,60 


Farm Board 




43 


Bin burned 




22,49 


Fat hydrolysis 




38 


Bleaching 




6,39 


Fats 




26 


Buffer value 




17 


Fatty acid (see . 
Feeding 


t \cid) 


13,88 


Carbohydrates 




24,26, 4 i 


Fermentation 




18 


Soluble 




7 


Flax 




19 


Carbon 






Flour 






Dioxide - 




18,19,28,67 


Flour 


7,8 


,16,17,24,25 


Disulfide 




51 




26,34. 


,38,39,40,43 


Carboxyl group 




4 






44,45,70,79 


Certificate final 


48 


Grade 




17,37 


Composition 






Heat treatment 


17 


Change during i 


aging 3,10 


Quality (see 


Quality) 








15,42,43,84 


Fumigants 
Fungus 

Growth 




2,3,20 

2S,29,51 

4,40,86 



35 



Item 



Item 



Germ 




40,73 


Oats 










27,42,60 


Defatted 




39 


Oil 










4,19,58,62 


Extraction 




49 


Oxygen 










67,80,91 


Natural 




39 


Supply, 


ei 


'fee 


t on s 


torage 37 


Germination (see Viability) 














Gliadin 




46 


Particle si; 


je 








43 


Gluten 4,17,24,35 


,37, 


,38,43 


Potassium bromate 






39,40 


44,47,57,70. 


,73, 


,82,89 


Phosphorus 










24 


Grade 






Phytin 










90 


Flour (see Flour) 






Protein- 










24,25,26,31,32 
33,34,46,90 


Hay 




88 


Proteolytic 


ac 


:tion 




7 


Heat 




35 














Heat damage (see Damage) 




Quality 












Heat treatment 




17 


Baking 








I,' 


7,8,17,26,28,43 


Heating 20,53,54; 


,55 : 


,62,91 












45,46,47,59,69 


Hermetically sealed (see 














73,77,61,82,83 


Containers ) 






Flour 










1 


Humidity 


16. 


,52,61 


Fumigani 


' j > 


effi 


3Ct 


on 


2,3,29 


Hydrogen-ion 






Grain 










15,48 


Concentration 


4, 


,17,25 


Milling 










59,82,83 


30; 


,44; 


,68,79 


Rancidity 










80 


Insect 






Respiration 










9,11,19,28,55 


Infestation 




49,50 


Rice 
Ripening 










74 
26,37 


Linoleic (see Acid) 






Rye 










13,19,27,42 


Linolenic (see Acid) 


















Linolic (see Acid) 






Saccharifies 


i tion 






20 


Lipoids 




44,73 


Sick wheat 
Soil 










21,22,23,86 
1 


Maltose 




27 


Soybeans 










33,34,58,37 


Maturity 


9^ 


,57,69 


Soybean 


me 


sal 






33,34 


Milling quality (see 






Specific gravi 


■ty 






47 


Quality) 






Starch 










22,27 


Moisture 11,16,17. 


.19; 


,23,35 


Sugar 










26,42,57,80 


49,50, 52, 6l! 


,62., 


,67,70 














72,77,80,83. 


,86. 


,87,91 


Temperature 






5. 


,12 


,15,16,32,38,45 


Cause of dcteriorj 


L— 










46,49 


,50,52,58,61,62 


tion 




9,15 








67. 


,69 


,74,82,86,87,91 


In aging 




4 


Tempering 










41 


Drying 




6 














Viet ting 




6,83 


Viability 










5,15,28,36,51 


Mus tines s 




21 












59,60,61,62,67 
72,81,82,86,87 


Nitrogen 




67 


Vitamin 










13 


Soluble 




17 


Vitamin 


A 








88 


Nutritive value 




13,31 


Vitreousnesg 


J 








83